Fixed compiling-warnings (MSVC2012): C4996(* was declared deprecated), C4305 (* truncation from 'double' to 'float'), C4018 (* signed/unsigned mismatch), C4800(* forcing value to bool 'true' or 'false').
Merge pull request #3741 from signmotion/develop

Fixed some compiling-warnings (MSVC2012).[ci skip]